Clinometer for well bores



Sept. 20, 1949. J. s. SWEARINGEN 2,432,224

CLINQMETER FOR WELL BORES I Filed Nov. 30, 1940 5 Shets-Sheet 3 .1. "8;GWEARINGEN INVENTOR.

ATTORNEY. I

5 Sheets-Sheet 4 MEN INVENTOR, 079M116. QM.

. ATTORNEY.

Sept. 20, 1949.

Filed Nov. 50, 1940 zai; 25"

v S p 1949- J. 5. SWEARINGEN- 2,432,224

CLINOMETER FOR WELL BORES Filed Nov. 30, 1940 5 Sheets-Sheet 5 J. S.SWEAR/N65 INV AT'I 'ORNEY.

Patented Sept. 20, 1949 CLINOMETER FOR WELL BORES Judson S. Swearlngen,Southton, Tex., assignor,

by mesne assignments, to Robinson Tool Company, Houston, Tex., acorporation of Missouri Application November 30, 1940, Serial No.367,911

4 Claims. 1

This invention relates to the drilling of wells by the rotary method andparticularly to a device for indicating at anytime during drillingoperations the departure of the well bore from the vertical.

In the drilling of wells by the rotary method and the subequentproduction of such wells it is highly desirable that the well bore bestraight throughout its length and also that the axis of the bore bevertical. During drilling operations it has been proposed to utilizewell surveying equipment to provide information regarding the departureof sections of the well from the vertical. Such procedure requires thata round trip of a well surveying instrument into and from the Well bemade whenever an observation is desired, an operation which is timeconsuming and expensive and which therefore dictates that considerablehole must be drilled between trips of the surveying instrument. If thereis progressive inclination of the section of the hole which is producedbetween trips of the surveying instrument corrective drilling operationsare less effective than they would be if the driller were apprized ofconditions at the instant inclination began. Furthermore if such sectionof inclined hole is to be rectified it is necessary to plug back and tosidetrack the hole in order to provide a continuous straight bore.

It has also been proposed to provide an indicating device whichthrottles or even entirely cuts off the circulation of the drillingfiuid so that the changes in pumping conditions indicates to the drillerthat inclination of the hole at the drill bit has been initiated. Whensuch condition is indicated, drilling is discontinued and steps aretaken toward the straightening of the hole. Such a device is disclosedin Patent No. 1,854,208 issued to Lynch et al., April 19, 1932.

The present invention is directed to an improved construction forproviding, and it is a primary object of the invention to provide, asimple and efficient instrumentality for indicating at any time duringdrilling the departure and amount thereof of the well bore from thevertical.

Another object is to provide such an indication without substantiallyinterfering with the circulation of drilling fluid and continueddrilling.

Still another object is to provide an indication of the amount ofinclination of the bore at any given level.

A further object is to obtain information of inclination of a well borewithout removing the drill string and drill bit from the bore.

A further object is to enable straightening of the bore hole.

The foregoing objects together with other objects will be apparent fromthe following description taken in connection with the accompanyingdrawings in which:

Fig. 1 is an assembly view showing a section of drill pipe equipped inaccordance with the invention;

Fig. 2 is an enlarged view partly in section showing the construction ofthe indicator unit of Fig. 1 and the relative position of such unit withthe throttling collar;

Fig. 3 is a sectional view'through the pendulum chamber of Fig. 2 withparts in their relative positions when fluid is pumped through the drillpipe during drilling;

Fig. 4 is a view similar to that shown in Fig. 3 but shows the relativeposition of parts when the inner assembly is moved to its uppermostposition;

Fig. 5 is a vertical sectional view through a modified form of theinvention;

Fig. 6 is an assembly view similar to that shown in Fig. 1 butillustrating a further embodiment of the invention;

Fig. '7 is a sectional view through the indicator unit shown inelevation in Fig. 6;

Fig. 8 is a developed view of the cam constituting an element of theconstruction of Figs. 6 and 7.

In Fig. 1 an embodiment of the invention is shown as comprising atubular member I such as a coupling in the drill pipe 2 or a portion ofa drill pipe section but is preferably the drill collar which isconnected tothe adjacent sections 3 and 4 of a drill stem having thepassage 5 for drilling fluid which is pumped during drilling in a manherwell known in the art. The bore 6 within the member I is slightly largerthan the passage 5 and has a throttling collar I0 mounted therein at itslower end. This collar has tapered areas I I and I2 at its oppositeends. Such areas merge inwardly into spaced annular ridges I3 and I4,

there being an annular groove i5 intermediate such ridges.

An inclination unit '23 is mounted in the bore ln art of drilling wellsby the rotary method. As above indicated the member 8 is preferably thedrill collar so that the assembly just generally I wax-ally through thedrill pipe 32 as is well known described is in proximity to the drillbit on the lower end of the drill pipe 2 so that any deviation of thebit from the vertical may be readily indicated at the instant suchdeviation takes place.

As best seen in Fig. 2 the cap member 22 is provided with a chamber 39which receives an expanslble member 8| attached to the upper end of thependulum chamber 32 from which projects a valve stem 33. The pendulumchamber 32 is spacd from the walls of the tubular member and is held inposition by its engagement with the lower end of the cap member 22 andthe upper end of a sleeve 21 which engages the lower cap member 25. Theupper cap member 22 and the sleeve 21 are reduced in cross section attheir adjacent ends and provided with breather openings 28 and 29respectively so that expansion and contraction of the expansible member3| may take place in a manner and for a purpose that will be more fullyapparent.

The valve stem 33 has an enlarged portion 34 which extends through thebottom of the cap member and a compression spring 35 engages a flange 36on the stem whereby the stem is constantly urged upwardly so that thevalve 31 at the lower end of the stem will move in succession to thepositions indicated in dotted outline at 38, 39 and 40.

In Figs. 3 and 4 which show the detailed constructlon of the pendulumchamber 32 it will be noted that the member 3i is attached to the head4| and that an opening 42 leads from the interior of such head to theinterior of the expansible member. A tubular member 43 is attached tothe head 4| at its upper end and to a plug 44 at its lower end, suchplug member having an opening to pass the valve stem 33 and beingprovided with a packing 45 and a gland member 43 whereby the chamber isentirely enclosed and adapted to contain a suitable fluid. such aslubricant. so that the parts therein to be more fully described mayoperate entirely within such fluid.

A cylinder assembly comprising upper and lower sleeves and II aresecured within the pendulum chamber, the sleeve 5| being of slightlysmaller diameter than the tubular member 43 whereby there is provided anannular chamber 52 between such members. The sleeve 5| is attached atits lower end to a plug 53 through which the valve stem 33 passes. Thisplug has a counterbore 54 at its lower end and a passage 55 leads fromthe interior of the cylinder assem- The passage 55 is enbly to suchcounterbore. larged at its upper end to receive a ball valve 55' so thatthe passage and valve cooperate to act as an upwardly opening checkvalve. A radial passage 56 in the plug member 53 permits fluid g 4 fromthe chamber II to flow by way of passages 57, 52 and 56 to the passageII and thence to the nether side of the piston assembly which'will v nowbe described.

The valve stem 33 has a head 3| at its upper end and such head isengaged by a piston assembly which comprises an outer piston member 32and an inner stepped sleeve 63 having a press fit therein so that thevalve stem and the piston assembly move as a unit. The steppedconstruction of the sleeve 63 provides annular shoulders 64 and S5 andan upper end surface 43.

Mounted within the chamber BI and above the piston assembly justdescribed is a pendulum 58 which is attached by means of a universalJoint 59 to the cap member 88 in coaxial alinement with such pistonassembly.

It seems apparent that when the piston assembly is in the position shownin Fig. '3 the pendulum is free to move within the chamber 60 and willremain in a vertical position even though the remainder of the unit beinclined from the vertical. If the housing is inclined and the pistonassembly is moved upwardly, such movement will be arrested at aposition, which is determined by the amount of inclination, by theengagement of the pendulum 58 with one of the surfaces 64, or 66. If theentire unit is in a vertical position the pendulum will obviously enterthe axial bore 61 in the piston assembly. Itis intended that thephysical dimensions of the partsof the unit will be such that apredetermined change in inclination, as for example one degree, willdetermine whether the pendulum will engage a given one of the steppedsurfaces or the one adjacent thereto.

In Fig. 4 the device is shown with the parts thereof in the relativepositions assumed when the piston assembly has been moved to itsuppermost position while the entire unit remains vertical.

In the operation of the device as above described it will be assumedthat such device constitutes a portion of a drfll pipe and thatdrlilling operations are inprogress. Under such circumstances the flowof drilling fluid through the member I impinges upon the valve member 31and holds the entire piston assembly in a downward position as shown inFigs. 1, 2 and 3. when an observation is to be made pumping of fluidpast the unit 20 is stopped or the rate of pumping -is reducedsufllciently that the piston assembly moves upwardly under the influenceof the spring 35.

As such movement takes place the liquid within the housing 32 flows fromthe chamber lll through the opening 51, the passages 52 and II to thechamber 54. This liquid lifts the valve 55'- in the passage 55 therebyadmitting such liquid to the nether side of the piston assembly.Attemtion is directed to the fact that volumetric changes within thehousing 32 will be compensated by movement of the conflned fluid throughthe passage 42 into the expansible member 3| as indicated in Fig. 4. Y

If the unit 20 is in a vertical position the pls ton assembly will riseand the pendulum 58 will enter the bore 61 therein. At the same time thevalve member 31 is lifted to the position indicated at 40 in Fig. 2.

When pumping is resumed in the drill pipe 3 the pump fluid will impingeupon the valve 31 and hence the valve and piston assembly will begin tomove downwardly against the force exerted by the spring 35. At the sametime the ball valve of time as for example from fifteen to twentyseconds although it is to be understood that the invention is notconfined to such timing interval. During this interval the valve movessuccessively through the positions shown at 39 and 38 and while suchvalve is passing the annular ridges I3 and II there will be throttlingof the pump liquid and accordingly pulsations transmitted to the pumpwill indicate to the driller that the valve is passing these restrictedareas.

For the assumed condition two impulses will be transmitted to the pumpand the driller will thus be apprised of the fact that the unit 20 wasin a vertical position when pumping was discontinued. If, however, theunit had been slightly inclined so that the pendulum 58 engaged theshoulder 64, the valve member 31 would have been held in the positionindicated at 39 and when pumping was resumed a single impulse wouldindicate that the unit was inclined an amount necessary to cause suchlimit of movement of the piston and valve assembly. In a similar mannera larger inclination would cause the pendulum 58 to engage the surfaceto and in .such event no throttling would take place when pumping wasresumed, and such fact would indicate that a material departure from thevertical had taken place.

It is to be understood that when a small inclination is shown to havetaken place corrective steps may be applied as for example by decreasingthe pressure applied at the drill bit, a practice by which it ispossible to correct small departures from the vertical while drilling.If, however, a considerably larger inclination is noted it may benecessary to withdraw the entire drill string and bit from the bore holeand utilize special bits which have been designed to straighten the wellbore.

The embodiment shown in Fig. operates in a manner similar to that justdescribed but this embodiment is such that the drilling fluid pumpedthrough the body 5 may also pass to the interior of the housing 32'within which a piston ii is mounted upon a tubular valve stem .33 towhich is attached the valve member 3?. The piston H is secured in placeupon the valve stem 33' by means of a cup member 12 into which the pendu4 lum 58 is intended to enter as above explained.

The piston and valve assembly is urged upwardly by means of thecompression sprin 35.

Passages i3 and id in the cap members 22' and 23 permit the ingress andegress of fiuid as the piston assembly moves within its housing 32'. Itis to be noted also that the passage J3 is larger than the passage itand permits pumped fluid to move downwardly through the bore '45 in thestem 73' and in this manner sedimentation within the chamber til isavoided.

It is also to be noted that the cup 72 as illustrated has but a singleshoulder 64' but it is to be understood that the inner surface of thecup 12 may be stepped in any desirable manner and that furthermore theannular ridges shown as l3 and i4 may be of any desired number so thatthe pulsations set up in the pumped fluid will indicate the inclinationof the unit 20' at the time pumping, was discontinued for the purpose ofmaking an observation.

In the embodiment illustrated in Figs. 6, '1 and 8 and housing unit 20"comprises two pieces of tubing 80 and BI which are joined at their innerends by the spider 82 having outwardly extending arms 83 which engagethe inner walls of the member I. The arms 25" on the lower cap 23"engage a tapered shoulder 84 on the interior of the member I so that theentire assembly is held in position within the member and with the valve31" normally held in spaced relation with the valve seat 85. The upperend of the tubing 80 is closed by a cap 86 having radial openings 81 toadmit fluid to the interior of the composite housing. The pendulum 58 issuspended from an axial projection on the cap 86.

A piston assembly generally referred to as 88 is movable within thehousing and comprises spaced pistons 89 and 99 mounted upon a centralshaft 9! which includes the tubular sleeve 92 and the valve stem 93. Arotatable cam Hill is positioned between the pistons 89 and 90 and has acam slot llll into which projects the end of a pin I92 in the spider 82.This cam is adapted to rotate about the sleeve 92 and, by virtue of itsslot construction llll, to serve a function that will more fully appear.

A compression spring I03 beneath the piston 90 engages an annular plateHM in the bottom of the housing and 'such plate surmountspacking Hi5 thespring W3. A stepped sleeve or cup 63' passes I 9 through the upperpiston 89 and secures the upper end of the piston assembly in assembledvrelation. This sleeve 53 serves the same purpose as the sleeve 63 shownin Fig. 3 and above described.

The operation of the embodiment of Figs. 6 and 7 will be made apparentby further reference thereto and to Fig. 8 which shows a development ofthe cam lllll showing in detail the configuration of the cam slot i 0!.From this development it will be seen that the slot Hll has a generallytransverse portion H0 at its upper end and a lower inclined portion HI,these portions being interconnected by intermediate slots NZ to H5inclusive which respectively include upwardly facing ledges H7. H8, H9and I20. Above the slots l H to H6 and in staggered relation therewithare pockets l 2| to 525 inclusive lying in a common plane except for thepocket I24 which extends upwardly for a suificient distance that thepiston and valve assembly move downwardly so that the valve 3?" engagesit seat when the pin E02 as-.

sumes the position i215.

Normally the cam lllll is urged upwardly by the spring m3 so that thepin H37. assumes the position indicated at i2l. As drilling fluid beginsto flow downwardly around the valve 37" the piston and valve assembly iscaused to move downward until the cam follower pin I 02 has taken theposition Hi, When the assembly is in this position the valve member 3?"is held above the valve seat as indicated in Fig. 6. When the fluid pumpis turned off or the rate of pumping is decreased suflicient that thepiston and valve assembly moves upwardly under the influence of thespring M3, the cam follower pin I00 moves through the cam groove to theledge I ll. When drilling fluid assau t 7 is again causedto flow the cammoves in a man-. ner that the pin I enters the pocket I22.

This process is repeated through positions II0,

' I23 and H9. The next downward movement of the piston and valveassembly will move the valve 31" downward until it seats upon the seat85 and the follower pin I00 will then have assumed the positionindicated at I26. In this position the flow of drilling fluid will beretarded as all fluid must pass through the restricted openings I30 inthe valve member 31" or through the openings 81 in the cap 86 and thencethrough the bore I3I in the piston and valve stem assembly. Thisrestriction of flow of drilling fluid can be observed at the surface asan increase of fluid pressure.

When the operator observes that the valve 31" has closed. the valve isreleased by stopping the flow of fluid for a short interval of time thusallowing the follower pin I02 to assume the position I20. Pumping isthen again resumed and the plunger and valve assembly will be stopped bythe engagement of the pin I00 in the pocket I25 and in this manner thevalve member 31" will be held off its seat as drilling proceedsnormally.

The movement of the cam I00 through the steps just indicated is retardedby the fluid entrapped within the chamber about the spring I03. Thisretardation of movements permits the pumped fluid to flow past the valvemember 31" for a considerable period of time, as for example five or tenseconds after pumping is resumed. When fluid is not flowing a similarlapse of time is required for the spring I03 to force the piston andvalve assembly upward to a new position.

When the follower pin I02 is in position I 25 the instrument is ready tomake a deviation measurement the next time the pump is stopped. When thepump is stopped the piston assembly moves upwardly. If the hole ismaterially inclined, say in excess of three degrees the pendulum 58 willengage the annular surface 66 of the cup 63' causing the upward movementof the cam to stop with the follower pin I02 in position I28. Thence onthe next downward movement of the cam I00 when the pumping of fluid isresumed, the cam will move downward so that the pin again assumes theposition I20, a condition which indicates the large inclination of theassembly.

If the inclination of the hole has exceeded two degrees but is less thanthree degrees the cam I00 on leaving position I25 will proceed upwarduntil the follower pin I02 reaches the position I29 at which point theassembly is stopped by the pendulum coming into contact with theshoulder 65 in the cup 03'. Subsequent turning on and off of the fluidpump will move the cam through positions I23, I I8 and thence toposition I26 which provides an indication of the inclination of the unit20".

In a similar manner a deviation of, for example. between one and twodegrees will cause the pendulum 50 to stop the upward movement of theassembly when the cam pin is at position I30, As already pointed out theamount of inclination will thereafter be indicated by the number oftimes the pumping is started and stopped before the valve 31" is againseated upon the seat 05.

Position I 25 is provided in order that there may always be an idleposition which can be used for drilling. If the driller wishes he neednot go through the complete cycle above outlined every time a pipeconnection is made. If he proceeds to drill in the customary manner hewill dad that the fluid pump will labor every fourth connection or every120 feet of drilling if standard 30 it. pipe lengths are used and if thedeviation of the hole is less than one degree. The labor of the pump isrelieved by stopping and starting the pump at which time the cam pin I02moves to the position I25 If the hole assumes a deviation of between oneand two degrees this event will take place every third connection orevery 90 ft. of drilling.

It seems apparent that if the deviation is greater than two and lessthan three degrees laboring of the pump will occur every secondconnection or every 60 ft. of drilling while if the deviation is greaterthan three degrees such laboring of the pump will occur every 30 ft. ofdrilling. The driller is thus automatically informed when the boredeviates from the vertical and may also taiiscertain the approximateamount of the devia- Attention is directed to the fact that, sinceordinary drilling fluids are inclined to jell in the absence ofagitation, circulation is provided through the unit 20" by the openings81 and the central bore I3I through the piston and valve assembly. Inthis manner the fluid around the pendulum is kept in agitation so thatit will not jell and interfere with the free movement of the pendulum.Although a specific preferred embodiment and modifications thereof havebeen disclosed herein it is intended that the invention shall not belimited thereto as the invention broadly comprehends the provision of asimple and eflicient device for indicating. at. any time duringdrilling. the departure and amount thereof of a well bore from thevertical.

What is claimed is:

1. In a device of the class described, an elongated member having a boretherein, an inclination unit mounted in said bore. said unit comprisinga housing, there being a passage for fluid between the member andhousing, a piston within said housing, a stepped cup movable with saidpiston, a pendulum suspended in the housing for engagement with thestepped cup when the member is inclined, spring means normally urgingthe piston and cup toward the pendulum, a stem attached to the pistonand extending outwardly through the housing, a valve member on said stemto move the stem outwardly when fluid is forced through the bore. andrestricted areas in said .bore to produce variable throttling of thefluid as the stem moves outwardly.

2. A device for indicating vertical deflection comprising, a tubularmember, an inclination unit mounted therein. said unit comprising ahousing of smaller diameter than the bore of said member to provide apassage therebetween, a stepped member movable longitudinally of andhaving leakage clearance with said housing, a pendulum suspending in thehousing and'engageable by said stepped member, spring means normallyurging said stepped member towards the pendulum, a stem attached to thestepped membr and sealably extending outwardly through the housing. abody comprising. a tubular member. an inclination unit mounted therein,said unit comprising a housing of smaller diameter than the bore of saidmember to provide a passage therebetween, a stepped member movablelongitudinally of said housing, a pendulum suspended in the housing andengageable by said stepped member, spring means normally urging saidstepped member towards the pendulum, a stem attached to the steppedmember and sealably extending outwardly through the housing, a body offluid within said housing to lubricate the enclosed elements and toresist external pressure on the housing, means comprising leakageclearance between the stepped member and the housing for restricting themovement of the stepped member from said pendulum, an enlargement onsaid stem exteriorly of the housing, and restricted areas in the bore ofsaid tubular member proximate said enlargement to produce variablethrottling of the fluid passing through the tubular member.

10 to resist external pressure on the housing, a. bypass for said fluidpast said stepped member, a check valve in said by-pass operable tofreely bypass fluid as said member moves toward the pendulum, anenlargement on said stem exteriorly of the housing, and restricted areasin the bore of said tubular member proximate said enlargement to producevariable throttling of the fluid passing through the tubular member, andmeans exposed to the fluid interiorly and exteriorly of the housing andadapted to alter the volume of the chamber within the housing tocompensate for the volumetric change produced by movement of the stem.

JUDSON S. SWEARINGEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

